Telephone system



Nov. 29, 1945. P. BAKKER 2,389,290

TELEPHONE SYSTEM 19 Sheets-Sheet 1 Filed Oct. 9, 1941 INVENTOR. P I ER BA K K E R BY I ATTORNEYS Nov. 20, 1945. P. BAKKER 2,389,299

TELEPHONE SYSTEM Filed 001. 9, 1941 19 Sheets-Sheet s FIG .23 2 57 if 204 f 16296 INVENTOR. PIER BAKKER ATTORNEYS W. 20, 1945. P. BAKKER TELEPHONE SYSTEM Filed Oct. 9, 1941 BACK FIG. 3A CONNECTOR 2o 32o -34| HOLD BATT- SLAVE 7 19 Sheets-Sheet 4 1N VEN TOR. PIER BAKKER ATTORNEYS Nov. 20, 1945. BAKKER 2,389,290

TELEPHONE SYSTEM Filed Oct. 9, 1941 19 Sheets-Sheet 6 HG M CONNECTOR 2O 453 am K BUSY R4 IN VEN TOR. PIER BAKKER BY mfwlhy, MM

ATTO R N EYS Nov. 20, 1945. P, BAKKER 2,389,290

TELEPHONE SYSTEM Filed Oct. 9, 1941 19 Sheets-Sheet '7 ANSFER PULSE CONTROLLED I N VEN TOR. PIER BAKKER BY mxw. M M

ATTORNEYS Nov. 20, 1945. P. BAKKER TELEPHONE SYSTEM Filed Oct. 9, 1941 19 Sheets-Sheet 9 CONTROL 05981 IN! 'EIVTOR. PIER BAKKER ATTORNEYS Nov. 20, 1945. P. BAKKER 2,389,290

TELEPHONE SYSTEM Filed Oct. 9, 1941 19 Sheets-Sheet 12 I To FIG.7

FINDER I r-- I l I I I LINE CIRCUIT llc TO FINDER I I I P. a. x. a LINE CIRCUIT h L "l6 TO FINDER I I I AUTOMATIC LINE REPEATER K DISTRIBUTOR START J J 1 I LN'I'ENTOR. PIER BAKKER ATTORNEYS Nov. 2U, 1945.

P. BAKKER TELEPHONE SYSTEM Filed Oct. 9, 1941 19 Sheets-Sheet 16 FIG. ll

Cll76 ,un 44 1174 cm? \m/ curs IFW ENTOR. PIER BAKKER BY W q'ff' ara ATTOPNEYS Nov. 20, 1945. BAKKER I 2,389,290

TELEPHONE SYSTEM Filed Oct. 9, 1941 19 Sheets$heet l7 SERVICE RESTRICTING NETWORK j 4 g} :0 o:

I F f' f v 4 6e 40 C389\ RES. SER.ST.\

INVENTOR. PIER BAKKER ATTO R NEYS Nov. 20, 1945. P. BAKKER TELEPHONE SYSTEM Filed Oct. 9, 1941 19 SheetsSheet 18 Q N O LLLLLL N N N) 0 FIG. l3

FIGJ3 M 7 m rm F F B M 6 6 m. H c... A w m G F H A w m m F F B M 6. m .H F F F 8 D 6 m H I. 9 G p c F F W F INVENTOR PIER BAKKER ATTOR NEYS TELEPHONE SYSTEM Pier Ba kker, Chicago, lll as'sign'or to Automatic Electric Laboratories, Inc, a corporation of Delaware Application October 9, i941, Serial No. 414,258 (Cl. 179-17) 9 Claims.

The present invention relates to telephone systems and has for one of its objects the provision of improved automatic switching apparatus of .the character utilized in interconnecting the' various lines of a relatively small exchange and in rendering the various services required of such an exchange.

It is an object of the present invention to provide in a system of the character described, improved facilities for providing difierent classes of service to subscribers who pay at different rates for the services received.

According to another object of the invention, an improved and exceedingly simple arrangement is provided for imposing, on a per. line basis, two or more difierent restrictions on the service rendered certain of the lines of the system.

In accordance with still another object of the invention the restrictions which are imposed on any particular line are all effected by equipment which is common to a plurality of the lines over a single control path which is individual to the line It is another object of the invention to provide for use in a system of the character described, an automatic line selecting switch which includes trunk hunting facilities and a directively controllable device which is concurrently operative with the trunk hunting facilities and functions to effect the selection of a distinctive ringing signal from a group of difl'erent ringing signals.

According to a further object of the invention the device for selecting any one of the different ringing signals is also utilized to block the operation of the trunk hunting facilities of the switch in order to limit the operation of the switch to the selection of a particular trunk in a given trunk group.

It is still another object of the invention to provide a line selecting switch of the character described wherein-provisions are made for automatically absorbing a portion of theimpulses of a predetermined trunk selecting digit and for directing the other impulses of the digit to the line selecting apparatus of the switch.

In accordance with another object of the invention, the ringing signal selecting device 'of the switch is also utilized to direct the required impulses of the trunk selecting digit to the group selecting apparatus of the switch and to absorb the remaining impulses of the digit.

It is another object of the invention to provide in a systemof the character described, an improved and exceedingly simple arrangement for selectively controlling the reversing of the battery connections to calling lines of the system.

According to another-object of the invention,

the line finders of the automatic switching equipmentf are equipped with normal post contact springs which function selectively to control the battery reversing facilities of the associated switching equipment on a line group basis.

It is another object of the invention to provide an improved and exceedingly simple arrangement for intercepting calls to certain of the lines of the system.

It is a still further object of the invention to provide a connector for use in a system of the character described, which includes an improved and exceedingly simple arrangement for revertively ringing a called substation in setting'up a reverting call connection between two substations served by the same line of the system.

The invention, both as to its organization and method of operation, together with further objects and advantages thereof, will best be understood by reference to the specification taken in connection with the accompanying drawings, in which Figs. 1, 2A, 23, 3A, 313, 4A, 43, 5A, 5B, 6A, 6B, and 7 to 14, inclusive, when combined in the manner shown in Fig. 15 illustrate. an automatic telephone system having embodied therein the features of the invention briefly referred to above.

Referring now more particularly to the drawings, the telephone lines, automatic switching apparatus and power supply and supervisory signaling equipment there illustrated may comprise, for example, a small unattended automatic exchange designed to serve a suburban area of limited population, which is geographically adjacent several large cities or towns each served by a central exchange. Inter-cflice trunks are used to provide communication facilities between the small community exchange and the oflices provided in the adjacent larger cities. For example, the automatic switching equipment of the community exchange is illustrated as having access to the automatic exchange 9 over a group of trunks which includes the trunk l3. Similar groups of trunks are provided which extend between the community exchange and each of the other central ofices. In order to provide the restricted service facilities, referred to above, two groups of trunks may be utilized to connect the illustrated community exchange with one of the distant central ofices in which is provided toll switchboard facilities. The single illustrated inter-omce trunk i3 is shown as terminating in 

